Bolen Basepads - available in 3mm, 4mm and 7mm lengths.  Features machined aluminum construction with a push pin design that eliminates accidental disassembly.  Use with Bolen followers and springs to obtain the highest capacity available.  The 3mm pad is for STI/SV/SPS/Rescomp 140mm and 170mm mags for a possible 21 rounds with .40 S&W and 30 rounds with 9mm and 38 SC when properly tuned.  The 4mm pad is for STI/SV/SPS/Rescomp 140mm and 170mm mags with slightly shorter length, for a possible 21 rounds with .40 S&W and 30 rounds with 9mm and 38 SC when properly tuned.  I've found the 4mm pad will generally work on most 140mm and 170mm STI and SV tubes and still allow the mag to fit in the USPSA gauge with minimal if any trimming of the pad.  Use the 7mm pad when overall mag length is of no importance, or for SPS 9mm and 38 Super134mm and 164mm mags.  The 164mm will hold 30 rounds and the 134mm will hold 21 rounds of 40 S&W.  Available in black only.

Bolen Followers - low profile, competition follower designed to allow the highest capacity available when combined with Bolen springs and basepads.  Spring locks into followers so there's no chance of the follower separating from the spring.  You'll notice there's enough material in the rear of the follower to trim down for use with 9mm spacers.  Note that these followers are designed for use with tuned mag tubes.  If you've got newer SV 140mm tubes all the components should drop right in and work fine.  If you're using the followers in STI tubes, 170mm SV tubes, or other tubes you may need to bevel down or taper the ribs at the bottom of STI mags, or the equivalent areas of other mags to ensure the follower doesn't bind up in the bottom of the mag.  This is necessary due to the fact that this follower travels much more deeply down into the mag tube than other followers. 

Bolen Magazine Springs - newly designed so each coil compresses and stacks into the neighboring coil to provide the highest capacity available in your magazines.  Best when combined with Bolens followers and basepads.  Available singly in 11 and 13 coil sizes or in 10 packs of each.  Single 11 coil springs are $10 each.  13 coil springs are $12 each.  11 coil 10 packs are $80 and 13 coil 10 packs are $100.