Does this unit work with a laser receiver? I'd like to use it outside to level a 20' short retainer wall.

Thank you for your question. The GLL 3-15 Self Leveling Laser is not compatible with any laser receiver. You may check out the GCL2-160 which is compatible with LR6 or LR7 Laser Receiver. For further assistance, contact us at 1-877-BOSCH99 (1-877-267-2499) from Mon-Fri 7A-7P CST.