An ALDI grocery store will soon open at 100 Powder Mill Rd. in Acton, filling the space previously occupied by Stop & Shop in the Powder Mill Plaza. The Acton location will be the 24th ALDI in Massachusetts and is part of the German supermarket chain’s broader U.S. expansion.

First-time ALDI shoppers should know a few things before their visit. Carts require a quarter deposit to unlock; shoppers get the quarter back when they return the cart to the corral. The system is designed to reduce cart retrieval labor and keep parking lots tidy.

ALDI keeps costs down in part by displaying products in their original shipping boxes rather than stocking shelves individually. The stores also carry roughly 90% private-label products and maintain a limited selection and small store footprint — a “no-frills” model the chain credits for its low prices.

Shoppers are encouraged to bring their own bags. Cashiers scan items and move them to the cart; customers bag their own groceries at counters near the exit, or can purchase reusable bags or use available boxes.

ALDI is also known for fresh produce, with fruits and vegetables sourced locally where possible.

A grand opening date has not yet been announced.