Picked up two pairs of these weight holders for my Anubis 2.0 Ultimate, and couldn’t be happier with them. Two pair seems like the right amount for me, but I do think I could fit another pair the rack in the future.

OVERVIEW
Universal 3x3 Compatibility – Fits any rack with 3" x 3" uprights and 1" holes, from any brand.
Heavy-Duty, Space-Saving Storage – Sold in pairs, each stainless steel peg offers 11.1" of loadable length and safely holds up to 600 lb of Olympic plates.
Made for Olympic Plates – Designed for standard Olympic plates, so your existing plates drop on and off with ease.
The pegs sit on a subtle 3° upward angle, making plates easier to slide on while helping keep them from slipping off.
Notes for ANUBIS Users:
On ANUBIS-2.0 Elite and ANUBIS-2.0 Ultimate, pegs can be mounted on the sides or on the back of the rear uprights—both positions stay clear of normal use.
On ANUBIS-2.0 Standard, pegs should be mounted on the back of the rear uprights only.
The ANUBIS series can accommodate up to three pairs of plate storage pegs at the same time.